Gauge for grinding machines



'April 26, 1949.-

P. J. FREDIN GAUGE FOR GRINDING MACHINES Filed Sept. 23, 1946 P/EVP/HE'J Ea p/1v ATTORNEY INVENTOR;

Patented Apr. 26, 1949 UNITED STATES Ffii'i'NT UFFICE 12 Claims.

The present invention relates to gages for use in setting up for tool grinding operations.

It is the general object of my invention to provide a simple and inexnensive device by means of which a tool, such as an end mill or other milling cutter may be quickly and conveniently adjusted and set relative to an abrasive wheel to grind the teeth thereof to any required angle.

This and other objects, as well as the many advantageous features of the invention will be better understood upon perusal of the following detailed description and by referring to the accompanying drawings, of which:

Fig. l is a side elevational View showing the device of my invention in position properly to align the teeth of an end mill with the peripheral surface of an abrasive wheel; and

Fig. 2 is a similar view illustrating a slightly modified form of the invention.

As illustrated in Fig. 1, an end mill A is set up for grinding the clearance angle of the bl .des thereof. The device of the invention comprises a frame 1 on which an arm 2 is mounted for sliding movement. In the lower extremities of the frame and the arm are cut oppositely directed notches l 2 for engagement with oppose cutting edges of the end mill, and it is important to note that these notches are in linear alignment with the axes of the cutter and the abrasive wheel C.

A lever 5 is pivotally mounte' on the frame l, in linear alignment with the notches l 2 This lever is symmetrical, the points 5 5* thereof being the same distance from its pivotal center. In addition, it is noticed that a pointer 5 rises from the upper o the lever for registration with a graduated scale of the frame.

In operation, the device is manually held and the arm 2 moved until the notches l 2 engage the cutting edges of the mill, whereupon a set screw 4 is tightened to clamp the arm rigidly in set position. The end mill, which has been loosely seated in the collet or chuck of the grind ing machine, is now rotated until the mill t-- gether with the gage assumes a horizontal position, as indicated on a spirit level 3 of the frame I. The end mill is thereupon moved toward the abrasive wheel C until the tips 5*, 5 of the lever 5 contact the peripheral surface thereof.

Finally, the end mill and the wheel are relatively moved vertically, while retaining the ends of the lever in contact with the wheel, until the pointer 5 registers with the graduation of the scale which corresponds to the clearance angle to be ground. In the zero position indicated in 1, the clearance angle would be ninety degrees.

The device above described is very compact and is ideal for use on end mills or small cutters. It can, of course, be used on large cutters also, by merely lengthening the frame l. However, since such larger age is heavier, occupies more space in the tool chest, and is more difiicult to handle, I prefenin connection with larger cutters, to use the modified gage illustrated in Fig. 2.

The frame I may remain unchanged, but the arm 2 has been removed and replaced by a bifurcated arm. it. The lower portion of this arm has been bent outward and a notch l2 sunk into its outer face to engage the arbor or hub of a cutter F. The bottom of this notch must be in linear alignment with the notch l the lever axis and the center of the abrasive wheel, and must be angularly symmetrical therewith.

When so proportioned, it is readily seen that this modified gage may be used on relatively large diameter cutters without increasing the length of the frame I, and that, in its application, it follows the steps above outlined. It has the advantage over the combination of Fig. 1 that it may be used alike on cutters having an even or an odd number of teeth. In order to use the device of 1 in connection with a cutter having an odd number of teeth, it will be necessary to calculate or to provide a table showing allowance to be made for the difference in angular tooth spacing in its relation to variations in cutter diameter.

It is seen that I have provided a simple and compact gage for cutter clearance angles which is convenient to operate and is adjustable to large and small cutters alike. I do not, however intend to be limited. to the exact proportions, shapes or arrangements shown, but reserve the "Fight to embody further modifications within the scope of the claims hereto appended.

I claim:

1. For use on a cutter grinding machine, a device for adjusting the position of the abrasive wheel relative to the cutter to be ground comprising, a frame having one end thereof laterally extending to form a guide and the other end thereof downwardly extending, an arm laterally movable on said guide, the lower ends of the frame and the arm having opposed notches for engagement with opposed teeth of the cutter to be ground, and a lever pivotally mounted on the frame, said lever having its end symmetrically spaced away from the pivotal center thereof to form gaging points for engagement with the abrasive wheel, the pivotal center of said lever being in linear alignment with said notches.

2. For use on a cutter grinding machine, a device for adjusting the position of the abrasive wheel relative to the cutter to be ground comprising, a frame having one end thereof laterally extending to form a guide and the other end thereof downwardly extending, an arm laterally movable on said guide, the lower ends of the frame and the arm having opposed notches for engagement with opposed teeth of the cutter to be ground, a lever pivotally mounted on said frame, said lever having its two ends symmetrically positioned relative to the center thereof for contact with the abrading wheel, the pivotal center of the lever being in linear alignment with said notches.

3. For use on a cutter grinding machine, a device for adjusting the position of the abrasive wheel relative to the cutter to be ground comprising, a frame having one end thereof laterally extending to form a guide and the other end thereof downwardly extending, an arm laterally movable on said guide, the lower ends of the frame and the arm having opposed notches for engagement with opposed teeth of the cutter to be ground, a lever pivotally mounted on the frame, said lever having its ends symmetrically spaced away from the pivotal center thereof to form gaging points for engagement with the abrasive wheel, the pivotal center of said lever being in linear alignment with said notches, a graduated scale on the frame, and a pointer on the lever for registration with the graduations of the scale.

4. For use on a cutter grinding machine, a device for adjusting the position of the abrasive wheel relative to the cutter to be ground comprising, a frame having one end thereof laterally extending to form a guide and the other end thereof downwardly extending, an arm laterally movable on said guide, the lower ends of the frame and the arm having opposed notches for engagement with opposed teeth of the cutter to be ground, a lever pivotally mounted on the frame, said lever having its ends symmetrically spaced away from the pivotal center thereof to form gaging points for engagement with the abrasive wheel, the pivotal center of said lever being in linear alignment with said notches, and a spirit level on the frame to indicate when said notches and the teeth of the cutter engaged by the notches are brought into horizontal align ment.

5. For use on a cutter grinding machine, a device for adjusting the position of the abrasive wheel relative to a cutter to be ground comprising, a frame having one end thereof horizontally extended to form a guide, an arm movable on said guide, said frame and arm having horizontally aligned elements for engagement with the cutter to be ground, a lever pivotally mounted on the frame, the ends of said lever being symmetrically spaced apart from its pivotal center to form gaging points for contact with the peripheral surface of the abrasive wheel, the pivotal center of said lever being in linear alignment with said elements.

6. For use on a cutter grinding machine, a device for adjusting the position of the abrasive wheel relative to a cutter to be ground comprising, a frame having one end thereof horizontally extended to form a guide, an arm movable on said guide, said frame and arm having horizontally aligned elements for engagement with the cutter to be ground, a lever pivotally mounted on the frame, the ends of said lever being symmetrically spaced apart from its pivotal center to form gaging points for contact with the peripheral surface of the abrasive wheel, the pivotal center of said lever being in linear alignment with said elements, and means for clamping said arm in position on the said guide.

'7. For use on a cutter grinding machine, a device for adjusting the position of the abrasive wheel relative to a cutter to be ground comprising, a frame having one end thereof horizontally extended to form a guide, an arm movable on said guide, said frame and arm having horizontally aligned elements for engagement with the cutter to be ground, a lever pivotally mounted on the frame, the ends of said lever being symmetrically spaced apart from its pivotal center to form gaging points for contact with the peripheral surface of the abrasive wheel, the pivotal center of said lever being in linear alignment with said elements, a graduated scale on the frame, and a pointer on lever for registration with the graduations of said scale.

8. For use on a cutter grinding machine, a device for adjusting the position of the abrasive wheel relative to a cutter to be ground comprising, a frame having one end thereof horizontally extended to form a guide, an arm movable on said guide, said frame and arm having horizontally aligned elements for engagement with the cutter to be ground, a lever pivotally mounted on the frame, the ends of said lever being symmetrically spaced apart from its pivotal center to form gaging points for contact with the peripheral surface of the abrasive wheel, the pivotal center of said lever being in linear alignment with said elements, a graduated scale on the frame, a pointer on the lever for registration with the graduati-ons of said scale, and a spirit level on the frame to indicate when the said elements are horizontally aligned.

9. For use on a cutter grinding machine, a device for gaging the position of the abrasive wheel relative to the teeth of a cutter to be ground comprising, a frame having a laterally extending portion forming a guide and a downwardly directed portion having a notch at the bottom thereof for engagement with a tooth of the cutter, an arm laterally movable on said guide, said arm being downwardly and outwardly directed and terminating in a V-shaped groove for engagement with the cutter arbor or hub, a lever pivotally mounted on the frame, the ends of said lever being shaped for contact with the periphery of the abrading wheel and being symmetrically positioned relative to the pivotal center of the lever, the notch of the frame, groove of the arm and center of the lever being in linear alignment.

10. For use on a cutter grinding machine, a device for gaging the position of the abrasive wheel relative to the teeth of a cutter to be ground comprising, a frame having a laterally extending portion forming a guide and a downwardly directed portion having a notch at the bottom thereof for engagement with a tooth of the cutter, an arm laterally movable on said guide, means for clamping the arm in position on the guide, said arm being downwardly and outwardly directed and terminating in a V-shaped groove for engagement with the cutter arbor or hub, a lever pivotally mounted on the frame, the ends of said lever being shaped for contact with the periphery of the abrading wheel and being symmetrically positioned relative to the pivotal center of the lever, the notch of the frame, groove of the arm and center of the lever being in linear alignment.

11. For use on a cutter grinding machine, a device for gaging the position of the abrasive wheel relative to the teeth of a cutter to be ground comprising, a frame having a laterally extending portion forming a guide and a downwardly directed portion having a notch at the bottom thereof for engagement with a tooth of the cutter, an arm laterally movable on said guide, said arm being downwardly and outwardly directed and terminating in a V-shaped groove for engagement with the cutter arbor or hub, a lever pivotally mounted on the frame, the ends of said lever being shaped for contact with the periphery of the abrading wheel and being symmetrically positioned relative to the pivotal center of the lever, the notch of the frame, groove of the arm and center of the lever being in linear alignment, a graduated scale on the frame, and a pointer on the lever for registration with the graduations of the scale.

12. For use on a cutter grinding machine, a

device for gaging the position of the abrasive wheel relative to the teeth of a cutter to be ground comprising, a frame having a laterally extending portion forming a guide and a downwardly directed portion having a notch at the bottom thereof for engagement with a tooth of the cutter, an arm laterally movable on said guide, said arm being downwardly and outwardly directed and terminating in a V-shaped groove for engagement with the cutter arbor or hub, a lever pivotally mounted on the frame, the ends of said lever being shaped for contact with the periphery of the abrading wheel, and being symmetrically positioned relative to the pivotal center of the lever, the notch of the frame, groove of the arm and center of the lever being in linear alignment, and a spirit level on the frame for indicating when said groove notch and pivotal center are horizontally aligned.

PIERRE J. FREDIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 458,922 Smith Sept. 1, 1891 1,224,836 Blainer May 1, 1917 1,283,868 Nefedov Nov. 5, 1918 1,567,134 Gosnell Dec. 29, 1925 1,687,649 Gillett Oct. 16, 1928 

